/* 
 * Copyright 2001-2009 Terracotta, Inc. 
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not 
 * use this file except in compliance with the License. You may obtain a copy 
 * of the License at 
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0 
 *   
 * Unless required by applicable law or agreed to in writing, software 
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 
 * License for the specific language governing permissions and limitations 
 * under the License.
 * 
 */

package org.go.trigger.calendar;

import java.util.Collections;
import java.util.Date;
import java.util.SortedSet;
import java.util.TimeZone;
import java.util.TreeSet;

import org.go.trigger.Calendar;

/**
 * <p>
 * This implementation of the Calendar stores a list of holidays (full days
 * that are excluded from scheduling).
 * </p>
 * 
 * <p>
 * The implementation DOES take the year into consideration, so if you want to
 * exclude July 4th for the next 10 years, you need to add 10 entries to the
 * exclude list.
 * </p>
 * 
 * @author Sharada Jambula
 * @author Juergen Donnerstag
 */
public class HolidayCalendar extends BaseCalendar {
	@SuppressWarnings("hiding")
	static final long serialVersionUID = -7590908752291814693L;

	// A sorted set to store the holidays
	private TreeSet dates = new TreeSet();

	public HolidayCalendar() {
	}

	public HolidayCalendar(Calendar baseCalendar) {
		super(baseCalendar);
	}

	public HolidayCalendar(Calendar baseCalendar, TimeZone timeZone) {
		super(baseCalendar, timeZone);
	}

	public HolidayCalendar(TimeZone timeZone) {
		super(timeZone);
	}

	/**
	 * <p>
	 * Add the given Date to the list of excluded days. Only the month, day and
	 * year of the returned dates are significant.
	 * </p>
	 */
	public void addExcludedDate(Date excludedDate) {
		Date date = getStartOfDayJavaCalendar(excludedDate.getTime()).getTime();
		/*
		 * System.err.println( "HolidayCalendar.add(): date=" +
		 * excludedDate.toLocaleString());
		 */
		this.dates.add(date);
	}

	@Override
	public Object clone() {
		HolidayCalendar clone = (HolidayCalendar) super.clone();
		clone.dates = new TreeSet(dates);
		return clone;
	}

	/**
	 * <p>
	 * Returns a <code>SortedSet</code> of Dates representing the excluded
	 * days. Only the month, day and year of the returned dates are
	 * significant.
	 * </p>
	 */
	public SortedSet getExcludedDates() {
		return Collections.unmodifiableSortedSet(dates);
	}

	/**
	 * <p>
	 * Determine the next time (in milliseconds) that is 'included' by the
	 * Calendar after the given time.
	 * </p>
	 * 
	 * <p>
	 * Note that this Calendar is only has full-day precision.
	 * </p>
	 */
	@Override
	public long getNextIncludedTime(long timeStamp) {

		// Call base calendar implementation first
		long baseTime = super.getNextIncludedTime(timeStamp);
		if ((baseTime > 0) && (baseTime > timeStamp)) {
			timeStamp = baseTime;
		}

		// Get timestamp for 00:00:00
		java.util.Calendar day = getStartOfDayJavaCalendar(timeStamp);
		while (isTimeIncluded(day.getTime().getTime()) == false) {
			day.add(java.util.Calendar.DATE, 1);
		}

		return day.getTime().getTime();
	}

	/**
	 * <p>
	 * Determine whether the given time (in milliseconds) is 'included' by the
	 * Calendar.
	 * </p>
	 * 
	 * <p>
	 * Note that this Calendar is only has full-day precision.
	 * </p>
	 */
	@Override
	public boolean isTimeIncluded(long timeStamp) {
		if (super.isTimeIncluded(timeStamp) == false) {
			return false;
		}

		Date lookFor = getStartOfDayJavaCalendar(timeStamp).getTime();

		return !(dates.contains(lookFor));
	}

	public void removeExcludedDate(Date dateToRemove) {
		Date date = getStartOfDayJavaCalendar(dateToRemove.getTime()).getTime();
		dates.remove(date);
	}
}
